446 DISSECTION OF THE ABDOMEN. 



second lumbar vertebra, and lies between the layers of the transverse 

 meso-colon. It has the following connections with the parts around : 



In front of it are the superior mesenteric vessels witli their plexus of 

 nerves. Beneath it lie the vena cnva and the aorta, with the pillars of 

 the diaphragm ; and the left renal vein is sometimes between it and the 

 aorta. Above it is the pancreas. 



PANCREAS (fig. 145, E ). The pancreas is situate behind the stomach, 

 and has numerous and complicated connections. Of an elongated form, it 

 extends across the spine from the spleen to the duodenum, and occupies 

 the left hypochondriac, the umbilical, and the right lumbar region of the 

 abdomen. 



The gland is covered anteriorly by the ascending layer of the transverse 

 meso-colon. It is in contact posteriorly with the aorta, the vena cava, 

 and the pillars of the diaphragm ; and it conceals likewise the splenic vein 

 and the commencement of the vena portse. 



Projecting above the upper border, near the centre, is the arterial trunk 

 of the ccelic axis : to the left of that vessel, along the same border, is 

 placed the splenic artery ; whilst to the right of it lie the hepatic artery 

 and the first part of the duodenum. At the lower border the superior 

 mesenteric vessels emerge opposite the crclic axis ; to the right of that 

 spot lies the third part of the duodenum, and to the left the inferior mesen- 

 teric ascending to join the splenic vein. 



The left end or the tail of the pancreas touches the spleen, and is placed 

 over the left kidney. The right extremity or the head is received into 

 the concavity of the duodenum, the two being partly separated by the 

 common bile duct and the pancreatico-duodenal arteries. This part pro- 

 jects above and below the body of the gland, like the head of a hammer 

 beyond the handle ; and the lower projecting piece is directed to the left 

 along the duodenum beneath the superior mesenteric vessels. 



CtELIC AXIS AND VENA PORT^E. 



A short branch of the aorta the cceliac axis, furnishes arteries to the 

 stomach and duodenum, the liver, pancreas, and spleen ; it subdivides into 

 three chief branches coronary, hepatic, and splenic. 



The veins corresponding with the arteries (except the hepatic) are col- 

 lected into one trunk the vena portae. 



Dissection. The vessels have been in part laid bare by the previous 

 dissection, and in tracing them out fully the student should spare the 

 plexuses of nerves around each. Supposing the liver well raised, he may 

 first follow to the left side the small coronary artery, and show its branches 

 to the oesophagus and the stomach. Next the hepatic artery, with the 

 vena portai and the bile duct, may be traced to the liver and the gall 

 bladder; and a considerable branch of it should be pursued beneath the 

 pylorus to the stomach, duodenum, and pancreas. Lastly, the splenic 

 artery, which lies along the upper border of the pancreas, is to be 

 cleaned ; and its branches to the pancreas, stomach, and spleen should be 

 defined ; this is a difficult task without the aid of some one to hold aside 

 the stomach and spleen. 



The veins will have been dissected for the most part with the arteries ; 

 but the origin of the vena portaj is to be made out beneath the pancreas, 

 and in front of the vena cava. 



The CCELIAC AXIS (fig. 145, c) is the first visceral branch of the ab- 



